I've never dueled a 57 earth mage pet, but I'd assume I could wreck one. That's with ~1300AC and a Shovel of the Harvest.
As Snaggles said: I can solo mobs that a mage pet cannot.
At 60, I would have at least 12 levels on the pet. (Max level pet is 48)
https://wiki.project1999.com/Pet_Guide#Earth_Pets
My max hit with the shovel is ~ 275 with no buffs. Flying kick is ~150? i think
Pet's max hit is 60, Kick damage is 28, Root Damage is 58.
With muzzle and Burnout, pet has 76% haste.
With epic and 40% worn, I have 80% haste.
We both have around 3k HP.
It seems close, but I think the real difference would be the level difference. I will land much more hits on a level 48 mob than the level 48 mob would land on me. Plus, I get mend and stonestance. Without any help from the mage I think it would be Monk wins with 40%+ HP remaining.
Epic pet is a different story. More HP, More melee damage, a stun, Better regen, a proc, better damage shield. That I am curious to see.